Coiled tubing systems are well known in the oil and gas industry. The term normally connotes a relatively small diameter continuous tubing string that can be transported to a well site on a drum or in a reel. Methods for inserting coiled tubing systems into existing wells are well known in the art. As oil and gas exploration technology continues to improve the demand for better wellbore information grows and there has been more interest in using coiled tubing to deploy more instrumentation into the wellbore, particularly pressure and temperature sensors.
As fiber optic telemetry develops there is increased need to install multiple fiber optic sensors inside coiled tubing. Each sensor may require its own FIMT (fiber in metal tubing), so there needs to be a method and devices to enable multiple FIMTs to be installed simultaneously in lengths of coiled tubing that can vary up to 10 km.
U.S. Pat. No. 6,116,085 to Moffatt describes a manufacturing method for inserting bundles of instrumentation, including thermocouples and pressure sensor wiring, in a coiled tubing system to create a continuous tubing string housing a plurality of pressure sensor assemblies connected to ports along the string and a plurality of thermocouples operative to measure temperatures along the string.
While some of these prior art methods provide workable solutions to the problem of installing sensor assemblies into coiled tubing there is a need for improved production techniques that do not require extensive cutting and welding steps in order to produce the coiled tube sensor assemblies. This need is growing as longer horizontal runs of tubing requiring more strength are being used.